IMAP, testing via Telnet
When troubleshooting an IMAP service, it's frequently helpful to use the telnet client to "speak" to the server directly, rather than using a mail client which won't give you the exact responses the server does. In this example, we will use telnet to connect to an IMAP server, log in as a user, list the user's available mailboxes, and check messages in one of them.
ph34r# telnet localhost 143 Trying 127.0.0.1... Connected to localhost.localdomain. Escape character is '^]'. * OK dovecot ready. A LOGIN firstname.lastname@example.org thisismypassword A OK logged in. A LIST "" "*" * LIST (\HasNoChildren) "." "INBOX" * LIST (\HasChildren) "." "Sent" * LIST (\HasNoChildren) "." "Sent.2006" * LIST (\HasNoChildren) "." "Sent.2007" a OK List completed. A SELECT inbox * FLAGS (\Answered \Flagged \Deleted \Seen \Draft) * OK [PERMANENTFLAGS (\Answered \Flagged \Deleted \Seen \Draft \*)] Flags permitted. * 1 EXISTS * 1 RECENT * OK [UIDVALIDITY 1103088195] UIDs valid * OK [UIDNEXT 1] Predicted next UID A OK [READ-WRITE] Select completed. A LOGOUT * BYE Logging out A OK Logout completed. Connection closed by foreign host.
Okay - we've just verified on a very direct level that the IMAP server we connected to answers incoming connections, successfully authenticates users, and successfully opens their inboxes - see the * 1 EXISTS and * 1 RECENT lines? That tells us that there is a single email in the inbox folder, and it hasn't been read yet. (We got "inbox" from the results of our LIST "" "*" command, which asked for a complete list of folders on this account.)